Hundreds of years after the large-scale battle against the Nokkers in the city of Renril, the world is unrecognizable. Thanks to the immortal Fushi's efforts in dormancy, he has successfully created a world with modern infrastructure where he and every living species can live in peace. When he finally awakens from his slumber, Fushi is elated to try everything this new world has to offer and revive his friends from the past. While exploring, Fushi runs into Yuuki Aoki, a lively middle school student, who is quick to welcome him and his friends into the house. As the group settles into their new home and learns more about the modern world, Fushi meets Mizuha, Yuuki's friend, who resembles someone familiar to him. It turns out that Mizuha is the descendant of the Guardians: the people whose only goal is to keep Fushi safe. Like her ancestors, she grows fond of Fushi, which brightens up her life. However, as bizarre events occur when Mizuha approaches Fushi, it becomes clear that this new world is far from perfect.

With its flickering streetlights, moldy back alleys, and noisy populace, the Second Kowloon Walled City, despite the squalor of its already-demolished predecessor, evokes a special kind of nostalgia that its residents find endearing. Amidst the walls of this fading yet beloved landscape lives Reiko Kujirai, a 32-year-old realtor deeply in love with her coworker, Hajime Kudou, who is two years her junior. Though they have their differences, the two get along well enough to experience the joys of the walled city together. However, everything starts to fall apart when Kudou, half-asleep, suddenly kisses Kujirai—seemingly reciprocating the feelings she has yet to confess. But when Kudou explains that he had mistaken her for someone else, Kujirai finds herself drawn into a series of events that lead her to a past she cannot remember.

There are some things that people are unable to say while they are alive; for these, there are shigofumi, letters carried from the world of the dead to the world of the living. When a person with strong emotions dies, they are able to create a shigofumi, whether their feelings are of love, longing, or resentment. It is the quiet and mysterious Fumika's job to deliver these messages from the departed. Along with her talking magic staff Kanaka, she ensures that each shigofumi reaches its intended recipient, even if that person does not want to face its contents. Fumika witnesses the tragedies of people, both dead and alive, and sees their deepest secrets revealed. What is unclear, however, are the details of Fumika's past. Who was she before she came to be a carrier of shigofumi?

During their last summer of elementary school, four friends decide to undertake a test of courage at their local graveyard. Before the test begins, Haruka Kaminogi makes a last effort to pull Yuu Gotou away from his controlling mother. While doing so, Haruka suddenly has a strange vision of blue snow followed by the appearance of an imposing silver-haired man. Later, a similar vision occurs at the graveyard to both Haruka and her friends before they try to escape what they assume are ghosts. Unbeknownst to the children, the people who appeared before them are Dragon Soldiers: an elite military group from a dimension known as La'cryma. The soldiers have traveled to this dimension to secure the Dragon Torque—an entity they believe to be their last hope for survival. However, both the Dragon Soldiers and Haruka are shocked to learn that the Dragon Torque is Haruka herself. She attempts to escape from the Dragon Soldiers as she finds her own last ray of hope—the strange silver-haired man who claims to be another version of Yuu himself.